Hydraulic control mechanism



Jan. 18, 1944. P. c. TEMPLE HYDRAULIC CONTROL MEGHANISM Filed OCT.. 31,1941 PA UL C. TEMPLE' Patented Jan. 1s, 1944 UNITED -HYDRAULIC CDNTROLMECHANISM I Paul C. Temple, Decatur, Ill., assignor to A. W.

Cash Company Delaware Decatur, Ill., a corporation of Applicationoctober 31, 1941, serial No. 417,283 (ci. eof54.5)

2 Claims.

This invention relates to hydraulic control mechanism, and moreparticularly to mechanism adapted to transmit motion from one element toanother element remote therefrom, through v the medium of a hydraulicfluid.

A mechanism of this type'includes a sender or compressor unit, and areceiver or motor unit. It is desirable that the motor unit shouldremain stationary except at such times as motion-is imparted thereto byactuating the compressor` unit. As a practical matter, however, itisvery dif- 'flcult to avoid some slight leakage of the hyv It is afurther object of the invention to provide a hydraulic control mechanismincluding a manually operable sender and a receiver, with r simple anddependable means whereby the operator may control the movements of thereceiver and ensure its remaining stationary when no movement isdesired.-

With these and other objects in view, as will be apparent to thoseskilled in the art, the invention resides in the combination of partsset forth in the speciication` and covered by the claims appendedhereto.

Referring to the drawing illustrating one embodiment of the invention,and in which like reference numerals indicate like parts,

Fig. l is a somewhat diagrammatic view of a hydraulic control mechanismconnected to a damper, with certanparts shown in section on the line l-Iof Fig. 2; and

Fig. 2 is a section on the line 2-2 of Fig; l.

The embodiment illustrated comprises a sender orcompressor unit I and areceiver or motor unit II. The sender I0 includes a hollow casing I2having a removable cover plate I4 andforming a reservoir for a suitablehydraulic fluid such as oil. Two vertical cylinders I5 and I6 aresecured to the bottom wall of the casing I2, with the upper portions ofthe cylinders extending into the casing. The upper ends of the cylindersare open. Within the cylinders I5 and I6 there are mounted two slidablepistons I8 and I9 respectively. These pistons are joined by connectingrods to the opposite ends of a rocker arm 22 secured to a horizontalshaft 23. This shaft is supported in two spaced bearings 24 in thecasing I2. One end of the shaft extends outside the casing, and to'thisend there is secured an upwardly extending handle or lever 26 which canbe swung back and forth to oscillate the shaft and thereby actuate'thepistons I8 and I9. Each of the cylinders I5 and I6 is provided with apo'rt 21 in the wall thereof so located that it will be uncovered whenthe corresponding piston is raised to its uppermost position. Theseports open into the interior of the casing I2, and they make it possiblefor air to .escape from the cylinders and for oil to enter the same. r

The receiver II comprises a hollow casing 23 having a bearing 29 thereinfor the support of a horizontal rotatable shaft 30. 'I'his shaft ex--tends outwardly. from the casing through a stufling box 32.- On theouter end of the shaft there is mounted an arm 33 which is connected bya link 34 to the operating arm 36 of a valve or damper 31 arranged tocontrol the flow of fluidv in a duct 38. A horizontal cylinder 48, issecured to the casing 28, the outer end-*of the cylinder being closedand its inner end being open and communicatingwith the interior of thecasing. Within the cylinder there is mounted a slidable piston 4I whichis joined by a connecting rod 42 to an arm 43 secured to the shaft30vwithin the casing 28. As the piston 4I moves from one end of thecylinder 40 to the other it will oscillate the shaft 30 and the arm 33,and this in turn will actuate the damper 31.

The receiver piston 4I is actuated by hydraulic pressure resulting frommovement of the sender pistons I8 and I9. For this purpose the lower endof the cylinder I5 is connected bya pipe 45 to the outer end of thehorizontal cylinder 40,

and the lower end` ofthe cylinder I6 is con-` nected by a pipe 46 andpassageway 41 to the inner end of the cylinder 4I). This passageway 41is formed partly in the cylinder 40 and partly in the casing 28. Thecylinder 4I!! is provided with'two ports 49 and 50 which are'so locatedas to be respectively uncovered by the piston 4I when it reaches itsoutward and inward travel limits. The port 49 is connected to the outerend of the cylinder by means of a passageway 5I,

and 'the port 58 is connected to the inner end of the cylinder by theheretofore described passageway 41. In order to prevent fluid fromentering the cylinder through these ports 49 and 58, they are providedwith spring loaded check valves 53 and 54 respectively.

It will now be apparent that if the handle 26 is moved to lower thepiston i8, oil will be forced through the pipe 45 into the outer end ofthe cylinder 40, moving the piston 4| inwardly. If the piston 4| reachesits inner travel limit before the piston .I8 reaches the bottom of itsstroke, the piston i8 can Anevertheless be made to coinplete its travelsince the extra oil.can escape through the port 50 and past the checkvalve 54. Similarly, if the handle 26 is moved in the opposite directionto lower the piston I9, oil will be forced through the pipe 46 into theinner end of lthe cylinder 40, moving the piston 4| outwardly.

-piston 4| and the dampere31 can be moved to any .desired 'position bymerely moving the handle 26.

In many cases `it is important to hold the damper 31 or other controlleddevice in a fixed position in spite of unbalanced forces tending tocause movement thereof. For this purpose it has been proposed `toprovide means for clamping the operating handle (such as the handle 26)in a It is found,

movement of the receiver piston will nevertheless occur even with thesender pistons stationary, since a slight leakage of the oil isunavoidable. Hence after a prolonged period it will be vfound thatthe-damper or other device has moved considerably out of position. Thepresent invention avoids this diiiiculty.

Referring now to Fig. 2, it will be seen that a stationary cylinder 56is connected to the receiver casing 26 by means of struts 51, thiscylinder surrounding the shaft 30 between the casing 26 and the arm 33.The outer end or head oi. the cyllnder 56 is shaped to provide a bearing5B for the haft 3|). Within the cylinder there is mounted a piston 60which is secured to the shaft 30 tov prevent relative rotation betweenthe shaft and the piston. These various parts are so constructed andarranged that by supplying pressure fluid to the cylinder 56 it ispossible to hold the piston 60 firmly against the inner end of thecylinder, the` resultant friction preventing rotation ofthe piston, aswell as the shaft 30. A pipe 62 is connected to the cylinder 56, and itwill be understood that this pipe may lead from a compressed air tank orother suitable source of pressure fluid. The piston 66 and cylinder 56forms a iiuid-actuated friction brake or locking device for 'theshaft30.

Means is provided whereby the operator may release the receiver lfromthe restraining effect of this locking device when he wishes to impartmotion to the damper 31. This may be accomplished by relieving the airpressure in the cylinder 56. For this purpose the pipe 62 is providedwith a restriction in the form of an oriiice plate 63, andmanuallycontrolled means is provided to allow air to escape from thecylinder at a faster rate than it can enter through the oriflce. Asshown in Fig. 2, one end of the sender` shaft 23 extends through annularsealing means `65 into a chamber 66 formed in a hollow plug 61screw-threadedinto the casing |2 in alignment I handle 26, this latterpassagel leading to a valve 13 which can be opened by means of a pushbutton 14 mounted in the upper end of the handle. The valve is normallyheld closed by a coiled compression spring 15, and when itis opened airis free to escape from the passage 1| into the atmosphere.

The operation of the invention will now be apparent from the abovedisclosure. With the valve 13 closed, the air pressure in `the cylinder56 of the receiver will be equal to that in the tank or other source ofsupply, and the piston 60 will be held firmly against the end wall ofthe cylinder, e'iiectually preventing any rotation of the shaft 30 ormovement of the damper 31 connectoffer negligible resistance to therotation of the shaft 30, and it will be possible to actuate thereceiver by simply moving the sender handle 26. When the damper 31 hasbeen moved to the position desired, the operator will release the pushbutton 14, allowing the spring 15 to close the valve 13. will thereuponincrease, and the brake will be applied to hold the damper fixed in itsnew position.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. Hydraulic control mechanism comprising a hydraulic motor having ashaft, a compressor unit,

. means to conduct hydraulic fluid from the compressor unit to the motorto turn the said shaft, a cylinder surrounding the shaft, a pistonwith.- in the cylinder and connected to the shaft to turn therewith,means to deliver pressure fluid to the cylinder to hold the pistonfirmly against one end of the cylinder and thereby prevent rotation ofthe piston and shaft, and manually controlled means associated with thecompressor unit to relieve the pressure in the cylinder.`

2. Hydraulic control mechanism comprising a hydraulic motor, acompressor unit having a pivotally mounted operating lever of hollowconstruction shaped to provide a chamber therein, means to conducthydraulic iiuid from the vcompressor unit to the motor to actuate thesame, a locking device associated with the motor to restrain movementthereof and arranged to be actuated by compressed air, a restrictedconduit to supply compressed air continuously to the locking device, aconduit connecting the locking device with the said chamber, and amanually'operable valve mounted on the lever to allow discharge of airfrom the chamber to the atmosphere.

' PAUL C. TEMPLE.

The air pressure in the cylinder 56

